Saturday, 19 January 2013

Lemurs 3: Ring-Tailed Lemur

Ring-Tail lemur plus baby, Bristol Zoo 2009
Probably the most well known lemur in the world, and one to be seen in practically all major and many minor zoos, the Ring-Tailed Lemur is in many respects rather unusual compared to its relatives. For one thing, although it can climb and leap from tree to tree with ease, it spends much of its time on the ground, a lifestyle otherwise known only among the extinct baboon lemurs, Archaeolemur. In diet it is unspecialised, feeding on fruits, seed pods, terrestrial plants and flowers, fungi, and a variety of insects and small vertebrates, although its favourit food in most of its range is the tamarind tree. This is probably why it does well in captivity – the range of foods it is adapted to eat means that feeding them on food obtained from cultivated crops and artificial diets will keep them in good condition, even before more scientific formulations were developed.

Tamarind tree and fruit
Unlike the mostly solitary mouse lemurs, most of the larger, diurnal lemurs are quite social, living in either family groups or larger societies. Ring-Tailed Lemurs are one of the most highly social of all lemurs, with typical group size of around 15 individuals. In Ring-Tail lemur society the females are the dominant sex, a situation common in lemurs (so the film Madagascar got that wrong). There are generally several males and several adult breeding females in each group, with separate hierarchies for males and females. In territorial fights between rival groups, females compete with foreign females, and males compete against foreign males.
Wild Ring-Tailed Lemurs, Madagascar
As one might expect with a highly social animal, Ring-Tailed lemurs have a plentiful supply of calls and other means of communication. One of the most common calls sounds rather like a cat, hence the scientific name Lemur catta, but there are also wails, clicks, and yaps. Given what is increasingly known of the information content in other animal calls, I suspect there are distinct predator alarm calls for different predators, but I am not aware of any studies on this.

Lemurs rely much more on olfactory communication than monkeys and apes do, and they are plentifully supplied with scent glands. Males have special spurs on their forearm (antebrachial) scent glands which they use to score grooves in bark and rub their scent in to mark territory. Males also engage in special olfactory combats called stink fights, where they anoint their tails with their scent and then wave them in a rivals direction to waft the scent at their opponent. Similar behaviour is also used in courtship displays during the breeding season.

The distinctive tail of the Ring-Tailed lemur is also of course a signal. It is especially useful when the group is travelling on the ground through grass and bushes – they walk with their tails held high so other group members can see their location over the surrounding grass.

Range of Ring-Tailed lemur
Typical habitat for Ring-Tailed Lemurs is gallery forest and dry forest with open grassland. They are found in the southern half of Madagascar, and avoid rainforest. Here at the zoo it is noticeable how much they detest wet weather and cold – they spend most of the winter months inside, only coming out for feeding and on dry days. They are very fond of sunbathing, typically sitting facing the sun with their arms spread out to give maximum exposure like so many bathers on the beach.

Ring-Tailed Lemurs sunbathing
The forests where they live are prone to drought, and in bad years they probably do not breed successfully. To compensate, when times are good they can become extremely productive, depending on the availability of food. On average, a typical female in the wild might raise one young every other year, and live to around 16 years. In captivity, they can have twins almost annually, and live to well over 25. One major concern for the captive population therefore is to avoid producing more young than there is room for, and the population needs to be managed with this in mind. Even so, the captive population is well over 2,500 individuals. Although habitat destruction and hunting is a threat in the wild, it is slightly less at risk than other lemurs, but the IUCN still classes it as Near Threatened.

Here at the zoo, Ring-Tailed Lemurs can be seen in the Lemur Walkthrough. This is closed for the winter, but their inside quarters (where they spend most of their time in the British winter) are on view to the public. They tend to sit up high, especially on top of the lights. Last year we had our first baby for many years, as our senior female is well into her twenties. We got a new male in, and expect the younger females in our group to breed in the coming year as well. The Lemur Walkthrough also houses two other lemur species, Mongoose Lemur and Red-Bellied Lemur, which will be posted about in the coming weeks.

(Images from wikipedia, Bristol Zoo website)

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